The changes in the Node 2.0 specification affect the messaging that occurs between Nodes. Because of the additional features and information carried in a Node 2.0 message, version 1.1 Nodes cannot communicate with version 2.0 Nodes. Furthermore, all of the existing data flows or exchanges that are currently deployed on the Exchange Network are built for communication between version 1.1 Nodes. The Exchange Network governance is currently engaged in an effort to document all of the changes that partners will need to make to many of their existing data flows in order to migrate them to a 2.0 Node. These changes will be documented on a flow-by-flow basis and will be incorporated into addenda to the Flow Configuration Documents (FCDs) for each data flow. Partners should note that these changes will be relatively minor and will not require any changes to the XML schema. That means you should not need to change any of your stored procedures or perform any new mapping activities.

timing of the transition

The Network governance will be producing the addenda to Flow Configuration Documents (FCDs) for each of the national regulatory flows including:

WQX - Water Quality Exchange
Facility Registry System (FRS)
Air Quality System (AQS)
Beach Notification
Toxic Release Inventory (TRI)
Substance Registry System (SRS)
Underground Injection Controls (UIC)
SDWIS
National Emissions Inventory (NEI)
RCRAInfo
ICIS-NPDES (eDMR)

Currently, the addendum for the WQX flow is the only one available. Others are in production and will be made available on the Exchange Network website in January 2009. U.S. EPA's Central Data Exchange (CDX) is now able to communicate with both version 1.1 and 2.0 Nodes. Please note that CDX will continue to support Node 1.1 data flows for the foreseeable future to allow adequate time for all partners to make the transition for all flows.

considerations when implementing node 2.0

Keep in mind that version 1.1 Nodes cannot communicate with version 2.0 Nodes. When you upgrade to a 2.0 Node, you will need to consider how that change will affect all of the different partners with whom you share information. Depending on your situation, you may need to maintain two endpoints (one for Node 1.1 and one for Node 2.0) until the transition to Node 2.0 is complete. Consider the following scenarios when planning to implement a Node and migrate your existing data flows:

• Your Node currently only shares information with U.S. EPA's CDX Node
  The vast majority of states, tribes, and other Network partners exchange information with U.S. EPA's Central Data Exchange Node. If this is the only partner with whom you routinely share information, you may use either a Node 1.1 or a Node 2.0 after November 2008. CDX will be capable of communicating with either Node version after this date. Once you implement a 2.0 Node, you can use the forthcoming FCD addenda to make the necessary changes to the configuration of your flows.

• Your Node shares information with CDX and at least one other partner Node
  If you use your Node to share information with partners other than CDX, you will need to consider their readiness to accept Node 2.0 flows when deciding to migrate your own flows to Node 2.0. Communicate with your other exchange partners so you are aware of their plans regarding Node 2.0. If you opt to implement Node 2.0 before your other partners, you may maintain two endpoints for your exchanges--one for flows with 1.1 Nodes and one for flows with 2.0 Nodes. Several of the Node products that are being developed will support endpoints for either version of the Node.